How many oxygen atoms are in 7 grams of carbon monoxide?

To find the number of oxygen atoms in 7 grams of carbon monoxide (CO), first calculate the molar mass of CO, which is approximately 28 g/mol (12 g/mol for carbon and 16 g/mol for oxygen). In 7 grams of CO, there are about 0.25 moles (7 g ÷ 28 g/mol). Since each molecule of CO contains one oxygen atom, this corresponds to 0.25 moles of oxygen atoms, which equals approximately 1.51 x 10²³ oxygen atoms (0.25 moles × 6.022 x 10²³ atoms/mole).